FDA approves major new Alzheimer’s drug, could delay symptoms for months

03 July 2024- The U.S. Food and Drug Administration has approved Kisunla (donanemab-azbt) injection for the treatment of Alzheimer’s disease. Treatment with Kisunla should be initiated in patients with mild cognitive impairment or mild dementia stage of disease, the population in which treatment was studied in the clinical trials.

Kisunla is administered as an intravenous infusion every four weeks.

Disease or Condition 

Alzheimer’s disease is an irreversible, progressive brain disorder affecting more than 6.5 million Americans that slowly destroys memory and thinking skills and, eventually, the ability to carry out simple tasks. While the specific causes of Alzheimer’s are not fully known, it is characterized by changes in the brain—including amyloid beta plaques and neurofibrillary, or tau, tangles—that result in loss of neurons and their connections. These changes affect a person’s ability to remember, think and speak.

Effectiveness 

The efficacy of Kisunla was evaluated in a double-blind, placebo-controlled, parallel-group study (Study 1, NCT04437511) in patients with Alzheimer’s disease. The patients had confirmed presence of amyloid pathology and mild cognitive impairment or mild dementia stage of disease. 1736 patients were randomized 1:1 to receive700 mg Kisunla every 4 weeks for the first 3 doses, and then 1400 mg every 4 weeks (N = 860) or placebo (N = 876) for a total of up to 72 weeks. The treatment was switched to placebo based on a prespecified reduction in amyloid levels measured by positron emission tomography (PET) at Week 24, Week 52, and Week 76.

Patients treated with Kisunla demonstrated a statistically significant reduction in clinical decline on the Integrated Alzheimer’s Disease Rating Scale (iADRS) compared to placebo at Week 76 in the overall population (2.92, p<0.0001), as well as on the iADRS component scales, the Alzheimer’s Disease Assessment Scale-Cognitive subscale (ADAS-Cog13) (-1.33, p=0.0006) and the Alzheimer’s Disease Cooperative Study – instrumental Activities of Daily Living (ADCS-iADL) scale (1.70, p=0.0001). Patients treated with Kisunla also demonstrated a statistically significant reduction in clinical decline on the Clinical Dementia Rating Scale – Sum of Boxes (CDR-SB) compared to placebo at Week 76 in the overall population (-0.70, p<0.0001).

At baseline, the study population had a mean age of 73 years, with a range of 59 to 86 years. Fifty-seven percent of patients were female, 91% were White, 6% were Asian, 4% were Hispanic or Latino, and 2% were Black or African American.

Safety Information 

The prescribing information includes a boxed warning for amyloid-related imaging abnormalities (ARIA). ARIA most commonly presents as temporary swelling in areas of the brain that usually resolves over time and may be accompanied by small spots of bleeding in or on the surface of the brain. ARIA usually does not have symptoms, although serious and life-threatening events rarely can occur.

Patients who are ApoE ε4 homozygotes have a higher incidence of ARIA, including symptomatic and serious ARIA, compared to heterozygotes and noncarriers. Testing for ApoE ε4 status should be performed prior to beginning treatment to inform the risk of developing ARIA.

There is risk of infusion-related reactions, with symptoms such as flu-like symptoms, nausea, vomiting and changes in blood pressure, and hypersensitivity reactions, including anaphylaxis (severe, life-threatening allergic reaction) and angioedema (swelling).

The most common side effects of Kisunla were ARIA and headache.

See full prescribing information for additional information on risks associated with Kisunla.